Coriander seeds are small, round seeds that come from the cilantro plant. They have a unique, citrusy and slightly sweet flavor that is commonly used in many different cuisines around the world, including Indian, Middle Eastern, and Mexican. The seeds can be used whole or ground into a powder, and are often used in spice blends, curries, stews, and soups. Coriander seeds are also a good source of iron, manganese, and dietary fiber.